Part 1: Implement ES6 function name property semantics

Issue #78

js/src/vm/AsyncFunction.cpp

@@ -116,7 +116,7 @@ js::WrapAsyncFunctionWithProto(JSContext* cx, HandleFunction unwrapped, HandleOb
     // Create a new function with AsyncFunctionPrototype, reusing the name and
     // the length of `unwrapped`.
 
-    RootedAtom funName(cx, unwrapped->name());
+    RootedAtom funName(cx, unwrapped->explicitName());
     uint16_t length;
     if (!unwrapped->getLength(cx, &length))
         return nullptr;
@@ -130,6 +130,9 @@ js::WrapAsyncFunctionWithProto(JSContext* cx, HandleFunction unwrapped, HandleOb
     if (!wrapped)
         return nullptr;
 
+    if (unwrapped->hasCompileTimeName())
+        wrapped->setCompileTimeName(unwrapped->compileTimeName());
+
     // Link them to each other to make GetWrappedAsyncFunction and
     // GetUnwrappedAsyncFunction work.
     unwrapped->setExtendedSlot(UNWRAPPED_ASYNC_WRAPPED_SLOT, ObjectValue(*wrapped));

js/src/vm/Debugger.cpp

@@ -9509,7 +9509,7 @@ DebuggerObject::name() const
 {
     MOZ_ASSERT(isFunction());
 
-    return referent()->as<JSFunction>().name();
+    return referent()->as<JSFunction>().explicitName();
 }
 
 JSAtom*

js/src/vm/GlobalObject.cpp

@@ -802,10 +802,10 @@ GlobalObject::getSelfHostedFunction(JSContext* cx, Handle<GlobalObject*> global,
         return false;
     if (exists) {
         RootedFunction fun(cx, &funVal.toObject().as<JSFunction>());
-        if (fun->name() == name)
+        if (fun->explicitName() == name)
             return true;
 
-        if (fun->name() == selfHostedName) {
+        if (fun->explicitName() == selfHostedName) {
             // This function was initially cloned because it was called by
             // other self-hosted code, so the clone kept its self-hosted name,
             // instead of getting the name it's intended to have in content

js/src/vm/Interpreter.cpp

@@ -1860,7 +1860,6 @@ CASE(EnableInterruptsPseudoOpcode)
 /* Various 1-byte no-ops. */
 CASE(JSOP_NOP)
 CASE(JSOP_NOP_DESTRUCTURING)
-CASE(JSOP_UNUSED182)
 CASE(JSOP_UNUSED183)
 CASE(JSOP_UNUSED187)
 CASE(JSOP_UNUSED192)
@@ -3482,6 +3481,19 @@ CASE(JSOP_TOASYNC)
 }
 END_CASE(JSOP_TOASYNC)
 
+CASE(JSOP_SETFUNNAME)
+{
+    MOZ_ASSERT(REGS.stackDepth() >= 2);
+    FunctionPrefixKind prefixKind = FunctionPrefixKind(GET_UINT8(REGS.pc));
+    ReservedRooted<Value> name(&rootValue0, REGS.sp[-1]);
+    ReservedRooted<JSFunction*> fun(&rootFunction0, &REGS.sp[-2].toObject().as<JSFunction>());
+    if (!SetFunctionNameIfNoOwnName(cx, fun, name, prefixKind))
+        goto error;
+
+    REGS.sp--;
+}
+END_CASE(JSOP_SETFUNNAME)
+
 CASE(JSOP_CALLEE)
     MOZ_ASSERT(REGS.fp()->isFunctionFrame());
     PUSH_COPY(REGS.fp()->calleev());
@@ -4343,7 +4355,7 @@ js::DefFunOperation(JSContext* cx, HandleScript script, HandleObject envChain,
         parent = parent->enclosingEnvironment();
 
     /* ES5 10.5 (NB: with subsequent errata). */
-    RootedPropertyName name(cx, fun->name()->asPropertyName());
+    RootedPropertyName name(cx, fun->explicitName()->asPropertyName());
 
     RootedShape shape(cx);
     RootedObject pobj(cx);
@@ -4991,7 +5003,7 @@ js::ReportRuntimeLexicalError(JSContext* cx, unsigned errorNumber,
     RootedPropertyName name(cx);
 
     if (op == JSOP_THROWSETCALLEE) {
-        name = script->functionNonDelazifying()->name()->asPropertyName();
+        name = script->functionNonDelazifying()->explicitName()->asPropertyName();
     } else if (IsLocalOp(op)) {
         name = FrameSlotName(script, pc)->asPropertyName();
     } else if (IsAtomOp(op)) {
@@ -5059,8 +5071,8 @@ js::ThrowUninitializedThis(JSContext* cx, AbstractFramePtr frame)
     if (fun->isDerivedClassConstructor()) {
         const char* name = "anonymous";
         JSAutoByteString str;
-        if (fun->name()) {
-            if (!AtomToPrintableString(cx, fun->name(), &str))
+        if (fun->explicitName()) {
+            if (!AtomToPrintableString(cx, fun->explicitName(), &str))
                 return false;
             name = str.ptr();
         }

js/src/vm/Opcodes.h

@@ -1870,7 +1870,16 @@
      *   Stack: =>
      */ \
     macro(JSOP_POPVARENV,          181, "popvarenv",            NULL,  1,  0,  0,  JOF_BYTE) \
-    macro(JSOP_UNUSED182,     182,"unused182",  NULL,     1,  0,  0,  JOF_BYTE) \
+    /*
+     * Pops the top two values on the stack as 'name' and 'fun', defines the
+     * name of 'fun' to 'name' with prefix if any, and pushes 'fun' back onto
+     * the stack.
+     *   Category: Statements
+     *   Type: Function
+     *   Operands: uint8_t prefixKind
+     *   Stack: fun, name => fun
+     */ \
+    macro(JSOP_SETFUNNAME,    182,"setfunname", NULL,     2,  2,  1,  JOF_UINT8) \
     macro(JSOP_UNUSED183,     183,"unused183",  NULL,     1,  0,  0,  JOF_BYTE) \
     \
     /*

js/src/vm/SelfHosting.cpp

@@ -2878,7 +2878,7 @@ CloneObject(JSContext* cx, HandleNativeObject selfHostedObject)
     RootedObject clone(cx);
     if (selfHostedObject->is<JSFunction>()) {
         RootedFunction selfHostedFunction(cx, &selfHostedObject->as<JSFunction>());
-        bool hasName = selfHostedFunction->name() != nullptr;
+        bool hasName = selfHostedFunction->explicitName() != nullptr;
 
         // Arrow functions use the first extended slot for their lexical |this| value.
         MOZ_ASSERT(!selfHostedFunction->isArrow());
@@ -2894,7 +2894,7 @@ CloneObject(JSContext* cx, HandleNativeObject selfHostedObject)
         // self-hosting compartment has to be stored on the clone.
         if (clone && hasName) {
             clone->as<JSFunction>().setExtendedSlot(LAZY_FUNCTION_NAME_SLOT,
-                                                    StringValue(selfHostedFunction->name()));
+                                                    StringValue(selfHostedFunction->explicitName()));
         }
     } else if (selfHostedObject->is<RegExpObject>()) {
         RegExpObject& reobj = selfHostedObject->as<RegExpObject>();
@@ -2977,10 +2977,10 @@ JSRuntime::createLazySelfHostedFunctionClone(JSContext* cx, HandlePropertyName s
         return false;
 
     if (!selfHostedFun->isClassConstructor() && !selfHostedFun->hasGuessedAtom() &&
-        selfHostedFun->name() != selfHostedName)
+        selfHostedFun->explicitName() != selfHostedName)
     {
         MOZ_ASSERT(selfHostedFun->getExtendedSlot(HAS_SELFHOSTED_CANONICAL_NAME_SLOT).toBoolean());
-        funName = selfHostedFun->name();
+        funName = selfHostedFun->explicitName();
     }
 
     fun.set(NewScriptedFunction(cx, nargs, JSFunction::INTERPRETED_LAZY,

js/src/vm/TypeInference.cpp

@@ -4541,7 +4541,7 @@ TypeScript::printTypes(JSContext* cx, HandleScript script) const
             uintptr_t(script.get()), script->filename(), script->lineno());
 
     if (script->functionNonDelazifying()) {
-        if (JSAtom* name = script->functionNonDelazifying()->name())
+        if (JSAtom* name = script->functionNonDelazifying()->explicitName())
             name->dumpCharsNoNewline();
     }
 

js/src/vm/TypedArrayObject.cpp

@@ -2870,7 +2870,7 @@ bool
 DataViewObject::defineGetter(JSContext* cx, PropertyName* name, HandleNativeObject proto)
 {
     RootedId id(cx, NameToId(name));
-    RootedAtom atom(cx, IdToFunctionName(cx, id, "get"));
+    RootedAtom atom(cx, IdToFunctionName(cx, id, FunctionPrefixKind::Get));
     if (!atom)
         return false;
     unsigned attrs = JSPROP_SHARED | JSPROP_GETTER;